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The Gurbantunggut Desert of Xinjiang is in temperate climate zone and its eco-environment is very fragile. With the exploitation and development of the oil-gas resources and the implementation of the desert highway and great engineering projects in the Gurbantunggut Desert the impact of human activities on the eco-environment has been increasingly significant. We compared the physical-chemical properties and vegetation community characteristics of Sandic Entisols from two artificial longitudinal dunes with a natural longitudinal dune in an area of engineering construction. Our results show that the depth of rainfall infiltration and soil moisture after rainfall for the artificial longitudinal dune, which lost vegetation (especially microbiological crust), is remarkably higher than the natural longitudinal dune and soil moisture on the artificial dune was subject to greater rates of evaporation. Salt concentration in the soil profile of the artificial dune is relatively uniform and reflects the homogenous environment that has resulted from mixing the soil. In comparison, Sandic Entisols usually show marked variation in salt content with depth, this was observed in the natural longitudinal dune. The nutrient levels of the natural longitudinal dune are higher than that of the artificial longitudinal dune, which is related to the distribution, density and health of the vegetation cover. After installing checkerboards to fix the artificial longitudinal dune, we found that ephemeral plants rapidly colonised the checkerboard environment. However, the re-establishment of shrub and semi-shrub plants required some rehabilitation measures, such as sowing seeds. Although the pioneering vegetation lacks the diversity of the natural vegetation, it creates beneficial conditions to establish additional plant species.
Thus, it can be seen that the desert vegetation and the physical and chemical properties of Sandic Entisols are greatly affected by the disturbance caused by engineering construction. However, our results show that if rehabilitation measures, such as fixing mobile sands and re-sowing seeds, are adopted during or soon after the construction period then the disturbed ecosystem still has some capacity for natural rehabilitation.
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